4-Path Mixer IIP3 calculations

Hi,

I'm trying to calculate IIP3 of a 4-path mixer. I've 6 PORTS in my circuit: 1 for RF, 1 for LO (I created quadrature signals using delay block of analoglib) and 4 PORTS on the output.

When I tried to simulate this using (qpss using hb), I got an error (screenshot attached)

My circuit:

Simulation test bench:
  

Error I got:

Please let me know the correct way to calculate these parameters for N-path mixers;

Regards
Arpit